The goal of this effort is to develop validated, mechanistic simulation tools to design high-force shape memory actuators using binary Ni-Ti and ternary Ni-Ti-Pt alloys.  Theory-experiment approaches are highlighted for each alloy. For the binary case, the predicted local stress in the vicinity of twinned martensite plates compares favorably with the dislocation structures observed in microcrystals deformed pseudelastically at room temperature. This preliminary result suggests that fine-scale plasticity is produced on a scale and orientation commensurate with individual martensite phases.  For the ternary case, detailed characterization of precipitates in aged materials informs both phase field modeling at the precipitate and single crystal scales, and microstructural finite element modeling at the polycrystalline scale. These examples show how phase transformations and crystal plasticity interact to determine the macroscopic, polycrystalline properties of shape memory alloys.